“Just as a cautious businessman avoids investing all his capital in one concern, so wisdom would probably admonish us also not to anticipate all our happiness from one quarter alone.”

Austrian physician and psychoanalyst of the late 19th and early 20th centuries, Freud is best known for founding psychoanalysis and exploring the unconscious mind through techniques like free association. His theories on the structure of personality—id, ego, and superego—and the role of early childhood experiences in shaping behavior remain foundational in psychology.